For home or field training! This 1/2-mile-range collar system has 16 levels of momentary (Nick) and continuous stimulations. Also has a vibration feature, a handy tool in dog training. And if you ever decide to get more dogs, the Micro-iDT PLUS can expand up to a 3-dog system. The collar unit is completely waterproof, while the transmitter is weather resistant. Fits small and large pooches comfortably.